The New Zealand Rugby Union (NZRU) have refused to bow to pressure to re-think its plans for the Air New Zealand Cup.

The country's leading club competition will undergo a re-vamp ahead of next season that will see the top division reduced to a 10-team competition. That controversial decision means four teams will be relegated from the top flight this season to form part of a newly-created six-team 'Division One' championship.

With the competition's popularity undergoing a renaissance, a range of stakeholders, particularly from the unions most under threat, have pleaded that the status quo remain in 2010.

However, chief executive Steve Tew said the NZRU was committed to the structure which he said all 14 provincial unions signed off on at the start of this year. That followed concerns over the financial viability of the competition. Principles agreed to then were a structure that featured promotion-relegation, a full round-robin of matches, no overlap with Super Rugby, and finished by the end of October with semi-finals and a final. A 10-team competition was deemed to best fit those principles.

Tew said criticism over the criteria used to decide which teams drop, a balance between financial and governance measurements along with on-field performance, was fair and also agreed to some time ago.

"(They) are reasonable and good indicators of who should be in this competition and who should not be," Tew said. "If those criteria mean your union isn't one of the 10 then you've got every opportunity with the support of your community to stick it back to us next year and win the (division one) competition."

It is becoming apparent there will be an outcry from the unions which get the chop, something Tew was braced for.

"There's an unfortunate inevitability about that but you can't cry away from decisions that are necessary and right," he said. "We hope they will reluctantly accept their situation, bite the bullet, buckle down and work really hard so they're in a good position to win the competition next year."

He said a collective agreement process with the New Zealand Rugby Players' Association had already begun surrounding a 10-team competition. There was also a focus on how to make the division one championship was as meaningful as possible.

One change to the structure announced two months ago was to a proposed "two up-two down" relegation system between the Air NZ Cup and division one. Instead just one team will be relegated, to be replaced by one promoted team.

Tew explained, "(There was) a fair amount of anxiety among provincial unions that we would create a lot of instability and uncertainty with that number of teams being in promotion or relegation zone."

Tew said five of the 10 Heartland Championship teams had expressed interest in being promoted into division one next year. They were King Country, Wanganui, Mid Canterbury, South Canterbury and North Otago.

The two highest ranked teams among them following this year's Meads Cup will then be promoted, although the NZRU board will first assess their financial viability. There will be no promotion/relegation between the Heartland and division one championships for at least the two following years.